Feed technology.DV reddy ,best notes ,exam oriented, Lecture notes of Nutrition

Download Feed technology.DV reddy ,best notes ,exam oriented and more Lecture notes Nutrition in PDF only on Docsity!

Feed technology

• (^) AAFCO Definitions
• (^) Complete feed: A nutritionally adequate feed for animals other than humans; by specific formula compounded to be fed as the sole ration and is capable of maintaining life and/or promoting production without any additional substance, except water , being consumed.
• (^) Concentrate: A feed used with another to improve the nutritive balance of the total and intended to be further diluted and mixed to produce a supplement or a complete feed.
• (^) Supplement: A feed used with another to improve the nutritive balance or performance of the total and intended to be (1) fed undiluted as a supplement to other feeds, (2) offered free-choice with other parts of the ration separately available or (3) further diluted and mixed to produce a complete feed.
• (^) Premix: A uniform mixture of one or more microingredients with diluent and/carrier. Premixes are used to facilitate uniform dispersion of the microingredients in a large mix.

• (^1). To make more profit : improved Feed efficiency 10% -20% by changing the method of grain processing.
• (^) 2. To alter particle size : increase their intake or digestibility. e.g. grinding. In some instances,
• (^) 3. To change moisture content : The moisture content of a feedstuff may need to be changed to make it safer to store (reduced to 10% level), more palatable, more digestible, or to prepare it for other processes (moisture level is increased).
• (^) 4. To change the density of feed : Bulky feeds (low density feeds)limiting energy intake. These are preferred in feeding of horses because they cause fewer digestive disturbances. Very bulky feeds are pelleted or cubed to increase energy density and feed consumption. Transportation cost is reduced and storage space required is less.
• (^) 5. To change palatability : Feeds are processed to increase acceptability and feed intake. Molasses, flavours and fats are added.

• (^) 6. To increase nutrient content : When used alone and in their natural state, only few feedstuffs meet the nutrient requirements of the animals.
• (^) 7. To increase nutrient availability : Starch (70-80% of DM) and protein appear to be less available in sorghum but newer technics improved availability. Pelleting of feeds increases the utilization of phosphorus for chicken and pigs.
• (^) 8. To detoxify or remove undesirable factors : Heating soybeans destroys the factors and protects enzyme, trypsin and chymotrypsin.
• (^) 9. To improve keeping qualities : High moisture grains may be preserved by either drying or chemical treatment (adding an organic acid), or they may be stored in oxygen limiting silos. Or as silage.
• (^) 10. To lesson moulds, salmonella, and other harmful substances : to avoid contamination. E.g.lessening aflatoxin contamination and toxin productionby adding Propionic and acetic acids

Type Of Mills

 Commonly used types. A. Hammer Mills:

• (^) These mills use impact grinding principle to reduce the particle size of feeds.
• (^) used for grinding of both concentrates and forages
• (^) The hammer mill consists of a cylinder or rotor made up of several plates keyed to the main shaft or axle and these plates, near the edge, carry the hammers. Outside the rotating cylinder is a perforated steel screen. The holes in this screen may be as small as 1/32" or as large as 2 or more inches
• (^) Hammer mills may be of the single, double or triple reduction type with either rigid or swinging hammers.
• (^) The double or triple reduction types have knives or blunt discs on one side of the rotor to chop the longer stemmed materials such as maize fodder or alfalfa into small pieces before they come in contact with the hammers (fed from a central opening)

• (^) The hammer tip may travel at a speed of 7000-

feet per minute. If the first impact of the hammers against

the feed does not break it up so that it will drop through the

screen, it rebounds and is again struck by the hammer

tips. This process continues until all particles are reduced to a

size that allow them to pass through the screen.

• (^) A fan or blower is usually used for product transport after

grinding, fan requires about 25-30% of the horse power

(HP) of the mill and also cools the stock being reduced.

• (^) Factors that Affect the Performance of Hammer Mills
• (^) 1. Diameter and shape of screen openings: if screen

openings are large performance increases

• (^) 2. Screen area: Production and efficiency are directly

proportional to area. Generally most hammer mills have 10-

square inches of screen area per unit HP.

• (^) 3. Moisture content : efficiency is inversely proportional to

the moisture content. It is uneconomical to grind grains at

moisture content higher than 12-14%.

• (^) 4. Peripheral speed (hammer tip speed): Most efficient

peripheral speed is between 7000 to 9000 ft/mt and at this

low speed mills produce more uniform grind but less fine and

coarser product.

• (^) 5. Kind of feed: Concentrates and Cereal grains are easier

to grind than roughages

• (^) 9. Number of hammers: Number of hammers in a mill definitely affects production and fineness. It is desirable to have 15 hammers per 100 mm of rotor. Each hammer is of 3 mm thick.
• (^) 10. Feed rate: An increased rate leads to coarser end product with increased capacity. feed rate is directly proportional to the applied power within the mechanical limitations of a given unit. The feed rate in most feed mills is controlled by an ammeter showing the current the motor is pulling
• (^) 11. Air flow through the mill: is directly proportional to efficiency optimum is 4000 cu. meters/sq. meter area of screen surface is sufficient.
• (^) Advantages of air flow are:
• (^) it reduces the temperature of the material, it vacates the place and may help in changing the direction of ingredient.
• (^) 12. Mechanical conditions : new screens and hammers are more efficient.
• (^) 13. HP of the motor : Performance is directly proportional to the HP of motor.

• 2. Roller Mills:
• (^) These are used in feed processing for the crimping or

crushing of grains. preferred for grinding of feeds for

efficient grinding and uniform particle size.

• (^) The roller mill consists of two rolls rotating in opposite

directions at the same speed or at different speeds. Rolls

are usually corrugated or serrated. If the rolls are

operated at the same speed, the reduction is mostly by

crushing. If the rolls have a speed differential, cutting

and shearing takes place.

• (^) Roller mills may have one, two or three pairs of rolls in a

strand.

Feed Mixing

• (^) Is most important operation in a feed mills. aim of mixing is to disperse the ingredients of a certain assortment (called formula) so that each small unit of the whole has the same proportion of each ingredient as in the original formula.
• (^) Feed Mixers are of Two Types
• (^) 1. Vertical batch mixer: It is used in thousands of feed mills and farms. They may be single screw or double screw for elevating the material. However, single screw mixer is popular. These are relatively inexpensive. They are little slower than horizontal mixers and are not used in larger feed mills. Normally screw is driven from the top. These units range in capacity from 0.5 to 5 tonnes
• (^) 2. Horizontal mixer: used in larger feed mills. This mixer has right and left hand flows which convey the material from one end of the mixer to the other while it is tumbled within the mixer. openings at several places along the bottom to aid in more rapid discharge. shaft is fitted with ribbons/paddles which thoroughly agitate and blend the ingredients solid / liquid to produce homogenous mix.

Horizontal mixer (ribbon type )

/ Ribbon

Peddles Motor Outlet Horizontal mixer (peddle type )